src/rtos/rtkernel.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2016-2023 by Andreas Fritiofson                         *
   5  *   andreas.fritiofson@gmail.com                                          *
   6  ***************************************************************************/
   7
   8 #ifdef HAVE_CONFIG_H
   9 #include "config.h"
  10 #endif
  11
  12 #include <helper/time_support.h>
  13 #include <jtag/jtag.h>
  14 #include "target/target.h"
  15 #include "target/target_type.h"
  16 #include "rtos.h"
  17 #include "helper/log.h"
  18 #include "helper/types.h"
  19 #include "rtos_standard_stackings.h"
  20 #include "target/armv7m.h"
  21 #include "target/cortex_m.h"
  22
  23 #define ST_DEAD     BIT(0)    /* Task is waiting to be deleted */
  24 #define ST_WAIT     BIT(1)    /* Task is blocked: */
  25 #define ST_SEM      BIT(2)    /*  on semaphore */
  26 #define ST_MTX      BIT(3)    /*  on mutex */
  27 #define ST_SIG      BIT(4)    /*  on signal */
  28 #define ST_DLY      BIT(5)    /*  on timer */
  29 #define ST_FLAG     BIT(6)    /*  on flag */
  30 #define ST_FLAG_ALL BIT(7)    /*  on flag and flag mode is "ALL" */
  31 #define ST_MBOX     BIT(8)    /*  on mailbox */
  32 #define ST_STP      BIT(9)    /*  self stopped */
  33 #define ST_SUSPEND  BIT(10)   /* Task is suspended */
  34 #define ST_TT       BIT(11)   /* Time triggered task */
  35 #define ST_TT_YIELD BIT(12)   /* Time triggered task that yields */
  36 #define ST_CREATE   BIT(13)   /* Task was created by task_create() */
  37
  38 struct rtkernel_params {
  39         const char *target_name;
  40         const struct rtos_register_stacking *stacking_info_cm3;
  41         const struct rtos_register_stacking *stacking_info_cm4f;
  42         const struct rtos_register_stacking *stacking_info_cm4f_fpu;
  43 };
  44
  45 static const struct rtkernel_params rtkernel_params_list[] = {
  46         {
  47                 "cortex_m",                     /* target_name */
  48                 &rtos_standard_cortex_m3_stacking,      /* stacking_info */
  49                 &rtos_standard_cortex_m4f_stacking,
  50                 &rtos_standard_cortex_m4f_fpu_stacking,
  51         },
  52         {
  53                 "hla_target",                   /* target_name */
  54                 &rtos_standard_cortex_m3_stacking,      /* stacking_info */
  55                 &rtos_standard_cortex_m4f_stacking,
  56                 &rtos_standard_cortex_m4f_fpu_stacking,
  57         },
  58 };
  59
  60 enum rtkernel_symbol_values {
  61         sym_os_state = 0,
  62         sym___off_os_state2chain = 1,
  63         sym___off_os_state2current = 2,
  64         sym___off_task2chain = 3,
  65         sym___off_task2magic = 4,
  66         sym___off_task2stack = 5,
  67         sym___off_task2state = 6,
  68         sym___off_task2name = 7,
  69         sym___val_task_magic = 8,
  70 };
  71
  72 struct symbols {
  73         const char *name;
  74         bool optional;
  75 };
  76
  77 static const struct symbols rtkernel_symbol_list[] = {
  78         { "os_state", false },
  79         { "__off_os_state2chain", false },
  80         { "__off_os_state2current", false },
  81         { "__off_task2chain", false },
  82         { "__off_task2magic", false },
  83         { "__off_task2stack", false },
  84         { "__off_task2state", false },
  85         { "__off_task2name", false },
  86         { "__val_task_magic", false },
  87         { NULL, false }
  88 };
  89
  90 static void *realloc_preserve(void *ptr, size_t old_size, size_t new_size)
  91 {
  92         void *new_ptr = malloc(new_size);
  93
  94         if (new_ptr) {
  95                 memcpy(new_ptr, ptr, MIN(old_size, new_size));
  96                 free(ptr);
  97         }
  98
  99         return new_ptr;
 100 }
 101
 102 static int rtkernel_add_task(struct rtos *rtos, uint32_t task, uint32_t current_task)
 103 {
 104         int retval;
 105         int new_thread_count = rtos->thread_count + 1;
 106         struct thread_detail *new_thread_details = realloc_preserve(rtos->thread_details,
 107                         rtos->thread_count * sizeof(struct thread_detail),
 108                         new_thread_count * sizeof(struct thread_detail));
 109         if (!new_thread_details) {
 110                 LOG_ERROR("Error growing memory to %d threads", new_thread_count);
 111                 return ERROR_FAIL;
 112         }
 113         rtos->thread_details = new_thread_details;
 114         struct thread_detail *thread = &new_thread_details[rtos->thread_count];
 115
 116         *thread = (struct thread_detail){ .threadid = task, .exists = true };
 117
 118         /* Read the task name */
 119         uint32_t name;
 120         retval = target_read_u32(rtos->target, task + rtos->symbols[sym___off_task2name].address, &name);
 121         if (retval != ERROR_OK) {
 122                 LOG_ERROR("Could not read task name pointer from target");
 123                 return retval;
 124         }
 125         uint8_t tmp_str[33];
 126         retval = target_read_buffer(rtos->target, name, sizeof(tmp_str) - 1, tmp_str);
 127         if (retval != ERROR_OK) {
 128                 LOG_ERROR("Error reading task name from target");
 129                 return retval;
 130         }
 131         tmp_str[sizeof(tmp_str) - 1] = '\0';
 132         LOG_DEBUG("task name at 0x%" PRIx32 ", value \"%s\"", name, tmp_str);
 133
 134         if (tmp_str[0] != '\0')
 135                 thread->thread_name_str = strdup((char *)tmp_str);
 136         else
 137                 thread->thread_name_str = strdup("No Name");
 138
 139         /* Read the task state */
 140         uint16_t state;
 141         retval = target_read_u16(rtos->target, task + rtos->symbols[sym___off_task2state].address, &state);
 142         if (retval != ERROR_OK) {
 143                 LOG_ERROR("Could not read task state from target");
 144                 return retval;
 145         }
 146
 147         LOG_DEBUG("task state 0x%" PRIx16, state);
 148
 149         char state_str[64] = "";
 150         if (state & ST_TT)
 151                 strcat(state_str, "TT|");
 152         if (task == current_task) {
 153                 strcat(state_str, "RUN");
 154         } else {
 155                 if (state & (ST_TT | ST_TT_YIELD))
 156                         strcat(state_str, "YIELD");
 157                 else if (state & ST_DEAD)
 158                         strcat(state_str, "DEAD");
 159                 else if (state & ST_WAIT)
 160                         strcat(state_str, "WAIT");
 161                 else if (state & ST_SUSPEND)
 162                         strcat(state_str, "SUSP");
 163                 else
 164                         strcat(state_str, "READY");
 165         }
 166         if (state & ST_SEM)
 167                 strcat(state_str, "|SEM");
 168         if (state & ST_MTX)
 169                 strcat(state_str, "|MTX");
 170         if (state & ST_SIG)
 171                 strcat(state_str, "|SIG");
 172         if (state & ST_DLY)
 173                 strcat(state_str, "|DLY");
 174         if ((state & ST_FLAG) || (state & ST_FLAG_ALL))
 175                 strcat(state_str, "|FLAG");
 176         if (state & ST_FLAG_ALL)
 177                 strcat(state_str, "_ALL");
 178         if (state & ST_MBOX)
 179                 strcat(state_str, "|MBOX");
 180         if (state & ST_STP)
 181                 strcat(state_str, "|STP");
 182
 183         thread->extra_info_str = strdup(state_str);
 184
 185         rtos->thread_count = new_thread_count;
 186         if (task == current_task)
 187                 rtos->current_thread = task;
 188         return ERROR_OK;
 189 }
 190
 191 static int rtkernel_verify_task(struct rtos *rtos, uint32_t task)
 192 {
 193         int retval;
 194         uint32_t magic;
 195         retval = target_read_u32(rtos->target, task + rtos->symbols[sym___off_task2magic].address, &magic);
 196         if (retval != ERROR_OK) {
 197                 LOG_ERROR("Could not read task magic from target");
 198                 return retval;
 199         }
 200         if (magic != rtos->symbols[sym___val_task_magic].address) {
 201                 LOG_ERROR("Invalid task found (magic=0x%" PRIx32 ")", magic);
 202                 return ERROR_FAIL;
 203         }
 204         return retval;
 205 }
 206
 207 static int rtkernel_update_threads(struct rtos *rtos)
 208 {
 209         /* wipe out previous thread details if any */
 210         /* do this first because rtos layer does not check our retval */
 211         rtos_free_threadlist(rtos);
 212         rtos->current_thread = 0;
 213
 214         if (!rtos->symbols) {
 215                 LOG_ERROR("No symbols for rt-kernel");
 216                 return -3;
 217         }
 218
 219         /* read the current task */
 220         uint32_t current_task;
 221         int retval = target_read_u32(rtos->target,
 222                         rtos->symbols[sym_os_state].address + rtos->symbols[sym___off_os_state2current].address,
 223                         &current_task);
 224         if (retval != ERROR_OK) {
 225                 LOG_ERROR("Error reading current task");
 226                 return retval;
 227         }
 228         LOG_DEBUG("current task is 0x%" PRIx32, current_task);
 229
 230         retval = rtkernel_verify_task(rtos, current_task);
 231         if (retval != ERROR_OK) {
 232                 LOG_ERROR("Current task is invalid");
 233                 return retval;
 234         }
 235
 236         /* loop through kernel task list */
 237         uint32_t chain = rtos->symbols[sym_os_state].address + rtos->symbols[sym___off_os_state2chain].address;
 238         LOG_DEBUG("chain start at 0x%" PRIx32, chain);
 239
 240         uint32_t next = chain;
 241         for (;;) {
 242                 retval = target_read_u32(rtos->target, next, &next);
 243                 if (retval != ERROR_OK) {
 244                         LOG_ERROR("Could not read rt-kernel data structure from target");
 245                         return retval;
 246                 }
 247                 LOG_DEBUG("next entry at 0x%" PRIx32, next);
 248                 if (next == chain) {
 249                         LOG_DEBUG("end of chain detected");
 250                         break;
 251                 }
 252                 uint32_t task = next - rtos->symbols[sym___off_task2chain].address;
 253                 LOG_DEBUG("found task at 0x%" PRIx32, task);
 254
 255                 retval = rtkernel_verify_task(rtos, task);
 256                 if (retval != ERROR_OK) {
 257                         LOG_ERROR("Invalid task found");
 258                         return retval;
 259                 }
 260
 261                 retval = rtkernel_add_task(rtos, task, current_task);
 262                 if (retval != ERROR_OK) {
 263                         LOG_ERROR("Could not add task to rtos system");
 264                         return retval;
 265                 }
 266         }
 267         return ERROR_OK;
 268 }
 269
 270 static int rtkernel_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
 271                 struct rtos_reg **reg_list, int *num_regs)
 272 {
 273         uint32_t stack_ptr = 0;
 274
 275         if (!rtos)
 276                 return -1;
 277
 278         if (thread_id == 0)
 279                 return -2;
 280
 281         if (!rtos->rtos_specific_params)
 282                 return -1;
 283
 284         const struct rtkernel_params *param = rtos->rtos_specific_params;
 285
 286         /* Read the stack pointer */
 287         int retval = target_read_u32(rtos->target, thread_id + rtos->symbols[sym___off_task2stack].address, &stack_ptr);
 288         if (retval != ERROR_OK) {
 289                 LOG_ERROR("Error reading stack pointer from rtkernel thread");
 290                 return retval;
 291         }
 292         LOG_DEBUG("stack pointer at 0x%" PRIx64 ", value 0x%" PRIx32,
 293                         thread_id + rtos->symbols[sym___off_task2stack].address,
 294                         stack_ptr);
 295
 296         /* Adjust stack pointer to ignore non-standard BASEPRI register stacking */
 297         stack_ptr += 4;
 298
 299         /* Check for armv7m with *enabled* FPU, i.e. a Cortex M4F */
 300         bool cm4_fpu_enabled = false;
 301         struct armv7m_common *armv7m_target = target_to_armv7m(rtos->target);
 302         if (is_armv7m(armv7m_target)) {
 303                 if (armv7m_target->fp_feature != FP_NONE) {
 304                         /* Found ARM v7m target which includes a FPU */
 305                         uint32_t cpacr;
 306
 307                         retval = target_read_u32(rtos->target, FPU_CPACR, &cpacr);
 308                         if (retval != ERROR_OK) {
 309                                 LOG_ERROR("Could not read CPACR register to check FPU state");
 310                                 return -1;
 311                         }
 312
 313                         /* Check if CP10 and CP11 are set to full access. */
 314                         if (cpacr & 0x00F00000) {
 315                                 /* Found target with enabled FPU */
 316                                 cm4_fpu_enabled = true;
 317                         }
 318                 }
 319         }
 320
 321         if (!cm4_fpu_enabled) {
 322                 LOG_DEBUG("cm3 stacking");
 323                 return rtos_generic_stack_read(rtos->target, param->stacking_info_cm3, stack_ptr, reg_list, num_regs);
 324         }
 325
 326         /* Read the LR to decide between stacking with or without FPU */
 327         uint32_t lr_svc;
 328         retval = target_read_u32(rtos->target, stack_ptr + 0x20, &lr_svc);
 329         if (retval != ERROR_OK) {
 330                 LOG_OUTPUT("Error reading stack frame from rtkernel thread\r\n");
 331                 return retval;
 332         }
 333
 334         if ((lr_svc & 0x10) == 0) {
 335                 LOG_DEBUG("cm4f_fpu stacking");
 336                 return rtos_generic_stack_read(rtos->target, param->stacking_info_cm4f_fpu, stack_ptr, reg_list, num_regs);
 337         }
 338
 339         LOG_DEBUG("cm4f stacking");
 340         return rtos_generic_stack_read(rtos->target, param->stacking_info_cm4f, stack_ptr, reg_list, num_regs);
 341 }
 342
 343 static int rtkernel_get_symbol_list_to_lookup(struct symbol_table_elem *symbol_list[])
 344 {
 345         *symbol_list = calloc(ARRAY_SIZE(rtkernel_symbol_list), sizeof(struct symbol_table_elem));
 346         if (!*symbol_list)
 347                 return ERROR_FAIL;
 348
 349         for (size_t i = 0; i < ARRAY_SIZE(rtkernel_symbol_list); i++) {
 350                 (*symbol_list)[i].symbol_name = rtkernel_symbol_list[i].name;
 351                 (*symbol_list)[i].optional = rtkernel_symbol_list[i].optional;
 352         }
 353
 354         return ERROR_OK;
 355 }
 356
 357 static bool rtkernel_detect_rtos(struct target *target)
 358 {
 359         return (target->rtos->symbols) &&
 360                         (target->rtos->symbols[sym___off_os_state2chain].address != 0);
 361 }
 362
 363 static int rtkernel_create(struct target *target)
 364 {
 365         for (size_t i = 0; i < ARRAY_SIZE(rtkernel_params_list); i++) {
 366                 if (strcmp(rtkernel_params_list[i].target_name, target->type->name) == 0) {
 367                         target->rtos->rtos_specific_params = (void *)&rtkernel_params_list[i];
 368                         return 0;
 369                 }
 370         }
 371
 372         LOG_ERROR("Could not find target in rt-kernel compatibility list");
 373         return -1;
 374 }
 375
 376 const struct rtos_type rtkernel_rtos = {
 377         .name = "rtkernel",
 378
 379         .detect_rtos = rtkernel_detect_rtos,
 380         .create = rtkernel_create,
 381         .update_threads = rtkernel_update_threads,
 382         .get_thread_reg_list = rtkernel_get_thread_reg_list,
 383         .get_symbol_list_to_lookup = rtkernel_get_symbol_list_to_lookup,
 384 };